Just change the input speed sensor and check the wires too but still the check engine is showing. If we will reset it, it works fine but if you turn off the vehicle and drive it again, the check engine shows up again. Can anybody tell us why we are still having this problem?
This TSB on the subject
An improperly functioning input speed sensor or output speed sensor on a 1999-2001 Sonata, 2001 Elantra, 2001 Santa Fe and 2001 XG300 may result in the following conditions: Harsh P-R or P-D engagement shock
Transaxle allows acceleration in 1st gear to 5000 rpm, then shifts into 3rd gear fail-safe
Check Engine light on
Diagnostic trouble codes: P0715 (no input speed sensor signal - open/short)
P0720 (no output speed sensor signal - open/short)
P1529 (TCM MIL request to ECM)
Check for DTCs in both the Engine and Automatic Transaxle menus. If you find: DTC REPAIR PROCEDURE REFERENCE
P0715Replace input speed sensor
P0720Replace output speed sensor
Fig. 1: Identifying Input And Output Speed Sensors
Courtesy of HYUNDAI MOTOR CO.
Drive the vehicle for at least two key-on to key-off driving cycles. If the codes do not reset, return the vehicle to the customer. If P0715 or P0720 return, go to step 2.
Use a DVOM to check the resistance of the wiring between the TCM and the input sensors and output sensors. If the resistance is: More than 1 ohm, repair or replace the wiring harness
Less than 1 ohm, go to Step 3.
Replace the transaxle control module (TCM).
November, 22, 2010 AT 3:19 AM
Shortly : make sure that timing belt is a justment 100% 100.